Assume that cost of keeping a cow for 1 day = c ,
cost of keeping a goat for 1 day = g Cost of keeping 20 cows and 40 goats for 10 days = 460
Cost of keeping 20 cows and 40 goats for 1 day = 460/10 = 46
=> 20c + 40g = 46
=> 10c + 20g = 23 —(1)
Given that 5g = c Hence equation (1) can be written as 10c + 4c = 23 => 14c =23
=> c=23/14 cost of keeping 50 cows and 30 goats for 1 day
= 50c + 30g
= 50c + 6c (substituted 5g = c)
= 56 c = 56×23/14
= 92 Cost of keeping 50 cows and 30 goats for 12 days = 12×92 = 1104 |